This application claims the benefit of Taiwan application Serial No. 091105310, filed on Mar. 20, 2002.
1. Field of the Invention
This invention in general relates to an embedded controller for controlling different programmable peripheral devices, and more particularly to an embedded control unit suitable for use in a notebook computer, which can be further integrated into a south bridge chipset by using the embedded control unit""s register-transistor-level (RTL) description after complete verification.
2. Description of the Related Art
Nowadays, the personal computer industry has reached maturity. Many computer components have already been standardized, resulting in the reduction in design difficulties. FIG. 1 schematically shows the structure of a typical desktop computer system. The desktop computer system includes a central processing unit 102, a north bridge chipset 104 and a south bridge chipset 106. In general, the south bridge chipset is also called the input/output (I/O) controller, which can be connected to many external peripheral devices. For example, an external keyboard 122 is coupled to the south bridge chipset 106, so as to receive user""s input data. Likewise, desktop computers are standardized so that the users can conveniently add other peripheral devices to the desktop computers. Different notebook computer manufacturers, on the other hand, implement respective circuit designs of their products in the form of a single main board, in order to make a breakthrough in the limitations on design specification, such as height, weight, and power consumption. In addition, the developers particularly add special functions related to various applications and peripheral devices to their products in order to provide some distinguishable product characteristics that are for the convenience of the users. For example, a dedicated e-mail indicator is provided to notify the user of the reception of e-mail as the indicator is on when an e-mail is received. In addition, dedicated keys are provided for the user to launch applications for various functions such as navigating the Internet, sending/receiving e-mails, or playing songs from a CD. Further, the special functions can be a special power saving mode, a special touch-sensitive pad support, reading battery capacitor and controlling the battery, special heat dissipation design, and so on. Such special functions are conventionally implemented by using an embedded controller (EC) including a microcontroller and a non-volatile memory, wherein the non-volatile memory can also be made either internally or externally. The design approach to the special functions is sufficient for the notebook PC designers to modify their programs flexibly. In order to design various special functions, the notebook PC manufacturers have to nurture hardware and software engineers. Unfortunately, such design approach thus increases the entire product complexity, the period for developing and testing firmware as well as hardware costs.
A conventional embedded control IC, which is employed in the structure of a typical notebook computer system, is illustrated in FIG. 2. The notebook computer includes a central processing unit 102, a north bridge chipset 104, a south bridge chipset 106, and an embedded control IC 208, wherein a number of built-in peripheral devices are controlled by the embedded controller IC 208. These built-in peripheral devices include, for example, a touch pad 210, an LED indicator 212, a fan 214, a battery 216, a built-in keyboard 218, and an optical disk drive 220. External peripheral devices such as an external keyboard 122 can also be connected to the notebook computer via a connection with the south bridge chipset 106. The LED indicator 212, for example, can be used as an e-mail indicator, a battery status indicator, or a hibernation mode indicator. The internal circuit of the embedded controller IC 208 includes a microcontroller. The embedded controller IC 208 is connected to the south bridge chipset 106 via a low pin count (LPC) cable.
It is therefore an objective of the invention to provide an embedded control unit capable of flexibly controlling different peripheral devices without programming firmware.
The invention achieves the above-identified objects by providing an embedded control unit, installed in a computer, to control a plurality of peripheral devices. The embedded control unit includes a plurality of peripheral controllers for controlling the peripheral devices, wherein each peripheral controllers can be enabled according to a selection signal. In addition, the embedded control unit includes a plurality of built-in register group sets for fine adjustment in the peripheral devices"" control so as to be compliant with different product brands and different specifications. The invention enables the design and development of notebook computers to reach the same maturity levels as the desktop computer shown in FIG. 1. It can also reduce the technology threshold that the downstream manufacturers have to cross so that the downstream manufacturers can produce their products more efficiently with the embedded control unit as well as making customization.
In other words, the invention is to provide an embedded control unit, to be installed in a notebook computer, in order to take the place of the conventional programmable microcontroller which is typical used in notebook computer designs. The embedded control unit includes a plurality of peripheral controllers, so as to control various peripheral devices usually used by notebook computers. With the respective settings of the non-adjustable internal registers, the peripheral controllers can be directly connected to the peripheral devices, according to the various different notebook computer design specifications.
In this way, the development process of the embedded controller is simplified by using an integrated circuit implementing a state machine to replace the conventional embedded controller that includes a microcontroller with an internal memory. Conventionally, the microcontroller is required to be programmed by firmware programmers, wherein firmware programmers are required to write source code for peripheral control in high-level computer language, and then the source code is complied into machine code and finally burned into the microcontroller""s memory that is installed either internally or externally. As a result, the invention enables reduced complexity of notebook computer product and a reduced period for developing and testing firmware as well as reduced hardware costs.
Other objects, features, and advantages of the invention will become apparent from the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings.